Variable-speed device having two movable flanges



A ril 9, 1940. c. E. JOHNSON ET AL VARIABLE SPEED DEVICE HAVING TWOMOVABLE FLANGES Filed July 9, 1935 4 Sheets-Sheet 3 llllllfllll x/JO V[/v VEN Toms CARL E-JOHMSO/V EARL Mz/vos/v/mu.

' able flanges,

Patented Apr. 9, 1940 VARIABLE-SPEED nnvror:

sumo

Pasadena, and Earl assignors hos Angelou,

Carl E. Johnson,

, Los Angeles, Calif trio Motors, ha,

MOVABLE ration of California Application July 9, 1935. Serial (Cl-Id-230.17)

6 Claims.

Our invention relates to variable-speed trans mission devices, and moreparticularly adapted to change driven shaft.

able-speed system ratio between a drive shaft and a to a varithe speedThe invention is applicable to various types of variable-speed systems,

but in the preferred embodiment we prefer to utilize the type ofvariable-speed unit including a V-belt or its equivalent in conjunctionwith one diameter pulley means,

including a pair or more variablepreferably of the type of flangemembers which can be moved toward and away from each other to change theeffective diameter of the pulley means. In existing'structures it iscommon to use a variable-diameter motor and a fixed-diameter pulley on apulley on, the drive shaft of a driven shaft connected to thevariable-diameter pulley by a V-belt, and in such systems thevariablediameter pulley is comprised of a conical flange fixed to thedrive shaft and a able axially on the conical flange movdrive shaft.Where such a variable-diameter pulley having an axially fixed and anaxially movable covered that when the changed by varying fl-angeis used,it is disdiameter of the pulley is the axial position'of the movableflange relative to the fixed flange, the

belt will not remain.

in the same planedue to the fact that the center of the pulley shiftsaxially with its change in effective diameter. This results in the beltcreeping up on the flange adjacent the plane in which the belt would beperpendicular to the of the device. various systems have been deviseddrive shaft, with consequent the belt and ineflicient operation. Toobviate these disadvantages,

in which the drive shaft is moved axially a distance proportionate tothe change. variable-diameter pulley, so belt at all times perpendicularSuch systems structure, and

in efiective diameter of the as to maintain the to the drive shaft.necessarily require. complicated it is a primary object of our inventionto maintain the belt of a variable-speed transmission device in a planesubstantially perpendicular to the shaft carrying the variable- 7without movin heretofore been ameter pulley axially as has the pulleyshaft necessary. We

prefer to accomplish this object by providing a variable-diameter pulleymeans each of which is toward and away from the other,

having two movaxially movable It is a further object of our device toprovide a variable-diameter axially movable is axially movable relativeto adjustment means for positively pulley means including two flangemembers, each of which the other, and

moving the HAVING TWO Mendenhall, to'Sterling Eleccalify. a conl lo.30,506'

adjustment means is operable from one side of 10 the pulley means.

A still further object of our invention is to furnish a variable-speedsystem including a motor having a drive shaft, a variable-diameterpulley means of the V-type on said drive shaft at one side of the motor,the pulley means including a pair of conical flanges axially movabletoward and away from each other, and adjustment means on the oppositeside of the motor from the pulley means for positively moving the pulleyflanges toward and away from each other to vary the effective diameterof the pulley means.

Another object of the invention lies in the provision of an adjustmentmeans for a variablediameter'pulley of the V-'type, including adjustablestops adapted to limit the axial movement of the flange members of thepulley means and to prevent overloading the bearings of the device.

Another object of the invention is to afford a motor having an axiallymovable drive shaft, there being a rotor fixed on the drive shaft whichmoves axially with the drive shaft and which is sufliciently longer thanthe stator of the motor to compensate for such axial movement of therotor.

A further-object of our invention is to provide a motor having anaxially movable drive shaft and having a rotor fixed with relation tothe stator of the motor, the motor being so constructed that the driveshaft can move axially relative to 40 the rotor.

Another object of the invention is to furnish a plurality ofvariable-diameter pulleys of the V- type on a shaft, the pulleys eachhaving two conical flanges movable toward and away from each other, andmeans for varying the effective diameters of said pulleyssimultaneously.

. In practice we have found that where a variable-speed pulleytransmission system is used in conjunction with a base adapted tomaintain a' desired tension in the belt by relatively moving the driveand driven shafts, and sudden torque is applied to the variable-diameterpulley means, as for example, by rapid starting of rotation of themechanism, or by some accidentca ing the slow rate of speed, It is astill further object= of our invention to ley flange members.

It is a further object of our invention to supply a novel base for avariable-speed pulley mechanism, which includes rollers operating intracks.

housing of the motor.

Other objects and advantages of our invention reside in the particularstructures disclosed, as well as in the general combinations, which willbe evident from the following description and claims.

Referring to the drawings:

Fig. 1 is an elevational view partially in section, of one form of theinvention.

Fig. 2 is a sectional elevational view of the base means shown in Fig.1.

Fig. 3 is a plan view, partially in section, of the base means of ourinvention shown in Figs. 1 and 2.

Fig. 4 is a detailed means shown in Fig. 1.

Fig. 5 is an alternative means.

Fig. 6 is an elevational view of an alternative embodiment of theinvention.

Fig. 7 is a sectional view taken on the line 1-1 of Fig. 6'.

view of the lubricating" form 01' lubricating Fig. 8 is an enlargedsectional view taken on the line 8-8 of Fig. 7.

Fig. 9 is an elevational view, partially in section, of an alternativeform of the invention.

Fig. 10 is an enlarged end view, partially in section, of the pulleymeans taken on the line Referring to Fig. 1, we show a motor l having IIat one end ing outer and inner II and a stator l2 fixed therein. bearingmeans I! at one end thereof for journaling a motor shaft l4 carrying arotor I6 fixed thereto by any suitable means.

The motor shaft l6 extends beyond the housthereof and carries pulleymeans ll of the variable-diameter V-type.

axially relative to each other but will rotate together. The outer endof the outer sleeve member 2| is provided with an enlarged portion 24having an annular recess 26 therein adapted to receive bearing means 26which may be in the form of a ball bearing structure havraces, the outerrace abutting against a shoulder 2'! in the outer sleeve member 2| andbeing held in fixed position relative to the sleeve member by a snapring 28 which fits into a suitable channel in the recess 25.

The pulley means I6 is adapted to be lubricated by a lubricating means29, shown in detail in Fig. 4, which includes a ball-valve 29a carriedby the outer sleeve member 2| and communicating through a longitudinalslot 29b in the inner sleeve member 20 with a lubricant resforced underpressure through the ball-valve 29a into the reservoir 29c, whichlubricant, when the device is rotated, isforced outwardly by centrifugalforce between the outer and inner sleeves 2| and 20 to lubricate theengaging surfaces of the sleeves. Lubricant will also pass between thesleeves 20 and 2| into the bearings 26 to keep them properly lubricated.An alternative form of lubricating means is shown in Fig. 5, in which aball-valve 29d is fixed in the end of a rod 50 and communicates througha central bore 50a and openings 50b withthe oil reservoir 290. Theoperation of the lubricating means shown in Fig. is substantiallysimilar to that shown in except that lubricant is forced through sleeves20 and 2|.

At the other end of the housing H from. the pulley means IS, anadjustment means 3|! is provided which is adapted to move the flangememhers I! and I8 axially, as will be described hereinafter. The endportion 3| oi. the housing H is provided with an annular projection 32having external left-hand threads 33 and internal righthand threads 34,the external threads 33 being adapted to receive an internally threadedactuating member 35, and the internal threads 34 being adapted toreceive an externally threaded actuating element 36. The actuatingelement 36 has an annular shoulder 31 adapted to engage a bearing 38which is held on the motor shaft H against a shoulder 39 thereon by asuitable snap ring III set in an annular channel in the motor edlysecured to the means of nuts 41.

46a which engages the actuating element 66to limit the inward movementof the actuating ele-' ment 66 relative to the pin members, and the pinmember 46 is 'provided with asuitable snap ring 45a which engages theouter side of the annular shoulder ment of the actuating element 66. Thepin members 45' and 46 also serve to limit the inward and outwardmovement of the actuating member 66. In practice it may be founddesirable to use more than two pin members similar to the pin members 45and 46, and we do not intend to be limited by our disclosure in thenumber of such pin members used. It is to be noted that by tightening orloosening the nuts 41, the length of the pin members 45 and 46 can bevaried, providing a convenient adjustable stop means tolimit the inwardmovement of the actuating means 66 so as to prevent overloading ofthebearing 66,"and this is an important feature of the invention. Theactuating member 65 is provided with a plu rality of handles 46 by whichthe actuating means may be conveniently rotated.

A rod member 66 extends through the motor shaft I4, being axiallyaligned therein and spaced from the internal surface of the motor shaft.One end of the rod member 56 is rigidly connected to the actuatingmember 66 by any suitable means such as lock nuts 5| threaded thereon,

the other end of the rod member being rigidly connected to a headelement 62 which journals the inner race of the bearing means 26, theinner race of the bearing being held in with a shoulder on the headelementby a able snap ring.

It will be seen that when the actuating member 35 is rotated in aclockwise direction, the internal threads thereon will cooperate withthe external left-hand threads "66 on the projection 32 to cause theactuating member to travel'outwardly on the projection, and the rod. 56will move axially to the right, as seen in Fig. 1, so as to cause thehead element 52 to force the bearing 26 to the right, and consequentlythe flange |6 will slide to the right with the outer sleeve 2|. Suchrotation of the ber 35 will also cause a rotation therewith of theactuating element 36 through the'pin members 45 and 46, and due to thecooperation of the external threads on the actuating element and theinternal right-hand threads 64 on the. projection 32, the actuatingmeans will move to the left on the pin members 45 and 46. Movement ofthe actuating element 66 will cause a corresponding axial movement ofthe motor shaft |4, since the bearings 66 are fixed thereto, and whenthe actuating element is moved to the left as described, the motor shaftM will move to the left and carry with it the flange, member l1 securedthereto by the inner sleeve 26. Thus, when the actuating member 35clockwise direction by means of the handles 46, the flange members l1and i6 will move simul-. taneously axially together, and when theactuating means ismoved in a counter-clockwise direction, the flangemembers will simultaneously move away from each other so as to provideany desired effective diameter for the variable-diamsuitthe direction ofactuating member 66 by bers. to chanle the The innerend of the 'pin'member 46 is provided with a suitable snap ring 61 to limit the outwardmoveto be secured engagement actuating memthe direction of the isrotated in a,

means [6.

movement of the flange memspeed ratio of the pulley shaft. The actuatingelement 66has 4| eter pulley means 16. As the flange members and 42therein which haveenlarged portions fl l1 and I6 are moved together orapart, the belt and 44 respectively. the op nings being adapted receivedtherein will move inwardly or outwardly to slidably receive pin members46 and-46threadfrom the center of the pulley, depending upon The motorI6 is supported on a base means 66 so as to be movable thereon which themotor shaft |4 lies.

plane in or otherwise.

rails 66 and a sunken centr rails 66 providing recessed tracks to eachother in the side mbers 62 and 66 havand 66 cooperate 6| to form trackformed at right angles rails. Cooperating track me track portions 64with the recessed tracks 66 and ing recessed to a carriage me Thecarriage member a1 portion channels in which carrier members 16 mayfreel move, as will be described fixed relative position the cooperatingtrack at an angle to a Them ,motor I6 is provided with a base 66 whichmay be of any suitable design and which is adapted mber 61 by bolts 61has side 66, the side-1l 66 and 6| hereinafter. The cooperating trackmembers 62 and 66 are held in in a base housing "by means of bolts 12projecting through the sides thereof and bolts 16 projecting members 62downwardly! into and 66. The

base housing 1| is provided with end portions 14 and 16 and has a topportion 16 which substancloses the base means.

tially For convenience only one of the carrier members 16 will bedescribed. it having a central spindle 11 disposed at right havingenlarged end portions 16 forme and 66 6| and 62 are carried in theopenings 16 and 66.

the openings and rollers the rollers 62 and so that the rollers 6| and66. The weight of will engage 61 and the supported motor and 62 willmaintain being so disposed that the tracks 66 and 64 6| will engage ,thetracks the carriage member II on the rollers 6| the rollers in rollingrelation in their respective tracks. The central spindle. 11 is providedwith a sprocket 64 rotatable onja hub 65 at the center thereof, thesprocket meshing with a chain 66 having its ends 61 suitably fastened tothe cooperating track me 66 by means of suitable pins.

a groove mber 62 in An inner chain 66 is provided in a suitable groove66a in the side rails 58, having its ends fixed thereto by 60 suitablepins,

and it also me shes with the sprocket 64. Such a chain and sprocketsystem is supplied members 16 and profor each of the two carrier videsmeans forsubstantially synchronizing and limiting the movement of causedby movement of the The carriage member 51 transverse bar 96 of a largecoil spring 6| the carrier members 55 is provided with carriage 51thereon.

to which is secured one end having its other end secured to the endportion 14 of the base housing 1|.

The spring 9| is disposed oppositely to belt connecting thevariablediameter pulley means IS with the device to be driven so as tomaintain a desired degree of tension in the belt, the carriage 51 ableon the carrier 16. Also connecte transverse bar 96 is a yoke rod 66fixed thereto which being freely movd to the 62 having a plungercarriesa piston 94 adapted to slide in a piston chamber 65 connected tothe end portion 15 of the base housing 1| by any suitable means. Thepiston chamber 95 is filled with a suitable fluid, such as glycer ne,

and the piston 64 is provided with a small opening 96 which communicateswith both sides the piston so as to permit the fluid to be force fromone side of the piston to the other upon longitudinal movement ofthe.plunger rod 33 and the piston. Since fluid can be forced through theopening 96 only at a slow rate, this piston mechanism provides means forpreventing rapid movement of the carriage 51 relative to the basehousing II andconsequentLy prevents rapid movement ofthe motor shaft I4relative to a driven shaft on a device to be driven so as to compensatefor peak overloads. and rapid starting or stopping of the pulley system,thus preventing breakage in the device.

An alternate embodiment of our invention is shown in Figs. 6, 7, and'8,in which the adjustment mechanism is adapted to be placed on the sameside of the motor as the variable-diameter V-type pulley which is ofimportance in some installations where space requirements necessitateone side of the motor being placed adjacent an article of machinery Inthis embodiment we prefer to use a standard form of motor I 00 having amotor shaft I 0| journaled in the motor housing by suitable bearingmeans adapted to permit axial movement of the motor shaft. As shown inFig. 7, the right end of the motor shaft IOI carries variable-diameterpulley means I02 of the V-type having flange members I03 and I04, theflange member I03 bein keyed to the motor shaft so as to be fixed relaive thereto and the flange I 04 being rotatable with the motor shaft butslidable thereon, the flange I 04 having a pin which extends through alongitudinal slot I05 in the motor shaft IOI and into a rod member I06which extends into a counterbored portion I06a of the motor shaft. Theouter end of the motor shaft MI is connected through suitable thrustbearings to an externally threaded riding member I01 having lefthandthreads, and the rod member I06 is connected at its outer end throughsuitable thrust bearings to a riding element I08 having externalright-hand threads.

The motor I00 has a. base IIO provided with an arm III having anupwardly extending portion II2' provided with a central opening II3through which the motor shaft I0! and the rod member I06 pass. Pins H4and H5 are secured to the upwardly extending portion N2 of the arm IIIand extend outwardly therefrom, being adapted to pass through openingsH6 and H1 respectively in the riding member I01 and through openings H8and H9 in the riding element I08, all of said openings Having aninternal diameter slightly greater than the external diameter of thepins H4 and H5 to permit the riding member and the riding element tomove axially relative to the pins. An actuatingelement I is provided inthe form of a cup-shaped member having a cylindrical wall IZI providedwith internal left-hand threads I22 and internal right-hand threads I23adapted to cooperate with the external threads of the riding member I01and the riding element I 08 respectively. A handle element I20 toprovide a convenient means for rotating the actuating element.

When the actuating element I20 is rotated in a clockwise direction, theinternal threads I22 cooperate with the external threads on the ridingmember I01 to cause the riding member to move axially to the right onthe pins H4 and H5, and the internal threads I23 will cooperate with theexternal threads on the riding element 08 to cause the riding element tomove axially to the left, the movements of the riding member and I24 issuitably secured to the actuating the riding element being equal andsimultaneous. As a consequence of the movement of the riding member I01and the riding element I08 on the pins H4 and III, the motor shaft illwill be moved axially to the right, and the rod member I56 will be movedaxiallyto the left so. as to decrease the effective diameter of thevariablediameter pulley means I02, the flanges I03 and I04 moving withthe motor shaft and rod. A counter-clockwise rotation ofthe actuatingelement I20, conversely, will cause theflanges I03 and I04 to separateto increase the efiective diameter of the pulley means I02. Thevariablediameter pulley means I02 is connected to a driven pulley I25 bymeans of abelt I26, and the speed relation between the variable-diameterpulley and the driven pulley may be varied by axially moving the flangesI03 and I04 relative to each other. In this embodiment, as in theembodiment shown in Fig. 1, the rotor I21 is fixed to the motor shaftIII and is sufliciently longer than the stator I20 so that when therotor is moved axially with the motor shaft, the electricalcharacteristics of the motor will not be changed, which is a furtherimportant feature of the invention. Likewise, as in Fig. 1, stop meansis provided to prevent overloading of the bearings, the riding memberI01 in its extreme leftward position engaging the portion II2 of the armIII, and in'its extreme rightward position engaging the riding elementI08. I

The motor I00 is carried by a base mechanism I30 consisting of anL-shaped platform I3I to" which the motor base H0 is secured by boltsI32 or other suitable means, and which has a downwardly dependingprojection I33 at each side thereof, each of which is pivoted to asubbase I34 by suitable means such as the hubs I35. A coil spring I36 isconnected between the end of the platform I3I and as part of the baseacts as a belt-tensioning device to maintain the desired degree oftension in the belt I26 at all times, similarly to the base means 55 ofFig. 1. It is to be understood, however, that in some installations thespring I36 can bedispensed with, since the weight of the motor I00,beingpivoted on thehubs I35, will act as a belt-tensioning means.

An alternative formof our device is shown in Figs. 9 and 10, in which weprefer to use a plurality of variable-diameter pulleys instead of thesingle pulley shown in the above described em bodiments. In Fig. 9 astandard form of motor I50 is provided having a hollow motor shaft I5Isuitably journaled therein in bearings, the shaft carrying a rotor I52of substantially the same length as the stator I53 fixed in the motorhousing. The ends of the motor housing provide journaling means for anaxially movable rod I54 which extends through the hollow motor shaftIsland a considerable distance beyond one end of the motor. The rod.I54is keyed to the motor shaft I5I by means of a key I55 which extendsthrough a longitudinal slot I56 in the motor shaft so as to permit therod to move axially relative to the motor'shaft but causing it to rotatetherewith. Fixed to the rod I54 so as to rotate therewith is a sleevemember I51 which carries thereon a plurality of flange members I58suitably fastened to the sleeve or formed integrally therewith. Slidablydisposed on the sleeve member I51 are a plurality of opposed flangemembers I53 fastened together by means of a pin I60 fixed to each of theflange members I59 by appropriate means and passing through an openingI6I in one of the flange members I66. A slot I62 is provided in thesleeve member I51. and a pin I63 passes through one of the flangemembers I59 and through the slot I62 and is keyed to the axially movablerod I54 so as to rigidly connect the flange members I56 to the axially vmovable rod. The slot I82 permits the flange members I59 to move axiallywith the rod I54 relative to the flange members I86 on the sleeve 10 I51but causes all of the flange members to rotate in unison.

The end of the rod I84 is connected through appropriate bearings I64a toan outer rider member I64 having external right-hand threads, and

5 the sleeve member I51 is connected through bearings I65 to an innerrider member I68 having external left-hand threads. Fixed to the base ofthe motor I56 is an outwardly extending arm I81 having a verticalportion I66 to which rods I69 and I16 are rigidly secured so as to passthrough openings I'll and I12 in the outer rider member I64 and openingsI13 and I14 in the inner rider 1 member I66 to prevent the rider membersfrom rotating relative to each other but permitting the rider members tomove axially relative to each other. An actuating element I16 provides a.cylindrical wall having internal left-hand threads I19 adapted tocooperate with the external threads on the inner rider member I66 andhaving internal right-hand threads I66 adapted to cooperate with theexternal right-hand threads on the outer rider member I64. A sprocketI62 is fixed on the actuating element I16 or may be formed integraltherewith which engages a chain I63 carried on an operating sprocketI64, the operating sprocket'being fixed to an actuating rod I66journaled in bearing supports I61 and I66 which are suitably fastened tothe housing of the motor I56 or formed integrally therewith. The a;actuating rod I66 is provided with handle means I61a which may be usedto rotate the rod and sprocket I64 and consequently thesprocket I62through the chain I63.

When the sprocket I62 is rotated in a clock- 5 wise direction, thethreads on the actuating element I16 will cause the inner and outerrider members I64 and I66 to move simultaneously toward each other,which in turn will cause the sleeve member I51 and the rod I54 to movelikewise so as to simultaneously vary the relative spacing of the flangemembers I56 and I59 of each of the pulleys to decrease the effectivepulley diameters. A counter-clockwise rotation of the actuating elementI16, conversely, increases the u effective-pulley diameters.

The motor I56 is supported by a base mechanism I96 substantially thesame as the base means 55 shown in Fig. l and for the same purpose. Aprimary advantage of the embodiment 50 shown in Fig. 9 lies in the factthat a plurality of variable-diameter pulleys may be utilized inconnection with cooperating belts leading to a pulley structure to bedriven, which finds particular utility where a heavy motor installationis re- 55 quired, since it permits smaller and more flexible belts to beused than would otherwise be possible and provides mechanism which cantransmit the high torque developed by a powerful motorwithout slippingor damaging the belts.

In Fig. 11 we show an alternative form of adjustment means for changingthe effective diameter of a variable-diameter pulley as above described,which may be substituted for the adjustment means illustrated in Fig. 1.In this form of the invention, a hollow motor shaft 266 is suitablyjournaled in bearings 26I in a motor housing 262 andhas one endoperatively connected to one flange of a variable-diameter pulley. Themotor housing 262 has an annular wall 263 provided with external.right-hand 8 threads 264 and internal left-hand threads 265. Theinternal threads 265 receive an externally threaded riding element 266which is connected through bearings 261 to the motor shaft 266 so as tomove axially therewith, and the external 10 threads 264 receive aninternally threaded cupshaped actuating. element 266. The actuatingelement 266 is supplied with pins 269 and 2I6 which extend throughopenings 2 and 2I2 respectively in the riding'element 266, the pins sbeing slidable in the openings but causing the riding element to rotatewith the actuating element. The actuating element is rigidly connectedto a rod 2 which extends through the hollow motor shaft 266 and is inturn operativey connected to the other flange of the. variable-diameterpulley which is to be adjusted. A set screw 2I5 carried by the actuatingelement 266 is adapted to engage a pin 2I6 set in the annular wall 263of the housing 262 to limit inward move- 26 ment of the actuatingelement, and provides a readily adjustable stopping means for theadjustment mechanism. A set screw 2" is carried by the riding element266 and is adapted to engage a stop pin 2I6 set in a projecting wall 2I9 of 80 the motor housing 262 to limit inward movement of the ridingelement, and also provides a readily adjustable stopping means for themechanism. Handles 226 are carried on the actuating element 268 andprovide convenient means for rotating the actuating element.

when the actuating element 266 is rotated in a clockwise direction, theriding element 266 being similarly rotated by the pins 269 and 2I6, theexternal threads 264 of the wall 263 will coop erate with the internalthreads on the actuating element to cause the actuating element totravel inwardly relative to the motor housing 262 until the set screw2I5 engages the pin 2I6 to prevent farther rotation of the actuatingelement. Similarly, with a clockwise rotation of the actuating element,the riding element 266 will rotate in the same direction, and theinternal threads 2651 on the wall 263 will cooperate with the externalthreads on the riding element to cause the aqtuating element to traveloutwardly relative to the housing 262. A counter-clockwise rotation ofthe actuating element 266 will cause the actuating element to. traveloutwardly and the riding ele-. ment to travel inwardly until the setscrew 2" engages the pin 2I8 to prevent farther rotation of theelements. Axial movement of the actuating element 266 and the ridingelement 266 is, of course, communicated through the rod 2 and the motorshaft 266 to the'flanges of the 00 pulley so as to change the effectivediameter thereof.

In Fig. 12 is shown another embodiment of the invention in which avariable-diameter pulley structure, together with a belt-tensioningbase,

is connected to an ordinary solid shaft motor to convert the motor intoa variable-speed unit. In this form of the invention a standard motor225, having a solid motor shaft 226, is supported on an auxiliary base221 carried by a base means 70 226 similar to the base shown in Fig. 1.An adjustment means 229 is carried by the base 228 and may be of anydesired construction, such as, for example, the adjustment means shownin Fig. '1, and is provided with a hollow shait 236 projecting therefromwhich journals a. rod "I extending. through the hollow shaft. The rod23l is 'spli'ned in a sleeve! which is fixed to the motor shaft 226 byany suitable means, such as a pin 23 3, soas to permit the rod to bemoved axially relative tothe motor'shaft but to cause it to rotatetherewith. A variable-diameter pulley 235 is carried on]' the hollowshaft 230 and has a flange 238 fixed. to the hollow shaft 230 by a pin231, and a flange 238 fixed to the rod 23I by a key 239 which extendsthrougha longitudinal slot 240 in the hollow shaft. Axial movement ofthe hollow shaft 230 and the rod 23l, produced by the adjustment means229 as described above in connection with Fig. 7, will cause an axialrelative movement of the flanges 236 and 238 to vary theeffectivediameter of the pulley 235. A primary advantage of this form of theinvention lies in the, fact that a standard form of motor can beconverted readily into a variable-speed unit without providing a specialmotor shaft,

It is to be understood that the different forms of base means may beinterchanged in the embodiments shown without departing from the spiritof our invention or that other belt-tensioning meansmay be used as asubstitute therefor without materially changing the scope of ourinvention. It is also to be understood that although we have shown therotor I52 and the stator I53 in Fig.. 9 to be of the same length, therotor being carried on the motor shaft, an auxiliary rotor shaft similarto the motorshaft |5l may be provided in either of the embodiments shownin Figs. 1, 7, or 12 so as to prevent the rotors therein frommovingaxially, without departing from; the spirit of our invention.Furthermore, it is to be understood that the multiple-belt pulley shownin Fig. 9 may be used in connection with the adjustment meansillustrated in the other embodiments without departing from ourinvention. Other interchanges of parts between the various embodimentsshown will be obvious to one skilled in the art, and we do not intend tobe limited to the specific structure illustrated and described.

We claim as our invention:

1. In combination: a motor housing; stator means within said housing;bearings at each end of said housing and axially movable therein; amotor shaft journalled in said bearings and axially movable; rotor meanscarried by said shaft and fixed thereto, said rotor means having alength substantially greater than the length of said stator means sothat an axial movement of said rotor means relative to said stator meanswill not affect the characteristics of said motor; a variable-diameterpulley of the V-type on said shaft, said pulley having two flanges oneof which is fixed relative to said shaft and the other of which isaxially movable on the shaft; and adjustment means for moving said shaftaxially so as to move axially said flxe'd flange relative to said otherflange to vary the effective diameter of said pulley.

2. In a variable-speed device, the combination of: a shaft; 2.variable-diameter pulley of the V- type on said shaft, said pulleyhaving two flanges both axially movable toward and away from each other;a tubular element having internal righthand and left-hand threadedportions; a first member disposed within said tubular element andthreadedly engaging said right-hand threaded portion; means operativelyconnecting said first member to one of said flanges; a second memberdisposed within said tubular element and threadedly engaging saidleft-hand threaded portion; means operatively connecting said secondmember to the other of said flanges; means for preventing relativerotation of said members; and means for rotating said tubular element soas to move said members axially to move said flanges toward or away fromeach other so as to vary theefi'ective diameter of said pulley.

3. In a variable-speed device, the combination of: a shaft; avariable-diameter pulley of the V-type on said shaft, said pulley havingtwo flanges both axially movable toward .and away from each other; atubular element having righthand and left-hand threaded portions, saidelement being axially aligned with said shaft; a first member'threadedly' engaging said righthand threaded portion of saidtubularelement; means operatively connecting said first member to one of saidflanges; a second member threadedly engaging said 1eft-hand threadedportion of said tubular element; means operatively connecting saidsecond member to the other of said flanges; and means for causingrelative rotation between said members and said element to cause saidmembers to move axially to adjust the relative axial position of saidflanges to vary the effective diameter of said pulley.

4. In combination: a motor housing; stator means within said housing;bearings at each end of said housing and axially movable therein; amotor shaft journalled in said bearings and axially movable; rotor,means carried by said shaft and fixed thereto, said rotor means havinga length substantially greater than the length of said stator means sothat an axial movement of said rotor means relative to said stator meanswill not affect the characteristics of said motor; a variable-diameterpulley of the V-type on said shaft, said pulley having two flanges, oneof which is fixed relative to said shaft and the other of which isaxially movable on the shaft;

of said housing and axially movable therein; a

motor shaft journalled in said bearings and axially movable; rotor meanscarried by said shaft and fixed thereto, said rotor means having alength substantially greater than the length of said stator means sothat an axial movement of said rotor means relative to said stator meanswill not affect the characteristics of said motor; a variable-diameterpulley of the V-type on said shaft, said pulley having two flanges, oneof which is fixed relative to said shaft and the other of which isaxially movable on the shaft; and adjustment means for moving said shaftand said other pulley flange axially in equal amounts and in oppositedirections so .as to move axially said fixed flange relative to saidother flange to vary the effective diameter of said pulley. e

6. In combination: a motor housing; stator means within said housing;bearings at each end of said housing and axially movable therein; amotor shaft journalled in said bearings and axially movable; rotor meanscarried by said shaft and fixed thereto. said rotor means having alength substantially-greater than the length of said stator means sothat an axial movement of said rotor means relative to said stator meanswill not afiect the characteristics of said motor; a variable-diameterpulley of the V-type on said shaft, said pulley having two flanges, oneof which is fixed relative to said shaft and the other of which isaxially movable on the shaft{ and adjustment means for moving said shaftand said other pulley flange axially in equal amounts and in oppositedirections so as to move axially said fixed flange relative to saidother flange to vary the effective diameter of said pulley, saidadjustment means including a tubular element having threaded portion ofsaid tubular element and operatively connected to said shaft, a secondmember threadedly engaging said left-hand threaded portion of saidtubular element and operatively connected to said other flange, andmeans for causing relative rotation between said members and saidelement to cause said members to move axially in equal amounts and inopposite directions.

- CARL E. JOHNSON:

EARL MENDENHALL.

